The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The ability of a digital controller to perform sophisticated algorithms makes it easy to apply adaptive control algorithms where system parameters can be adaptively adjusted in response to system behavior to achieve better performance. An adaptive controller is therefore intuitively a controller that can modify its behavior after changes in the control plant or in the environment. Conversion efficiency is one of the most important specifications for power supplies. Adaptive efficiency algorithms are much easier implemented with digital controllers in power supplies.
With the increased switching frequency of switching power supply, the switching-related power loss keeps increased resulting in lower power conversion efficiency. Among those switching-related power losses, switching loss dominates. In order to reduce the switching loss, many topologies have been developed. As a part of switching-related loss, the drive loss of switching devices is relatively independent of load. The drive loss usually does not play the key role at full load conditions. However, at very light load, the drive loss makes up a much higher percentage of the total power loss, especially at high-current high-switching-frequency applications, because low on-resistance FETs are used with the result of high total gate charge Qg and drive loss. Multiple FETs in parallel also increase the total gate charge and drive loss.